Description

The door_create() function creates a door descriptor that describes the procedure specified by the function server_procedure. The data item, cookie, is associated with the door descriptor, and is passed as an argument to
the invoked function server_procedure during door_call(3C) invocations. Other arguments passed to server_procedure from
an associated door_call() are placed on the stack and include argp and dp. The argp argument points to arg_size bytes of data and the dp argument points to n_descdoor_desc_t structures. The attributes argument specifies attributes associated with the newly created door. Valid values for attributes are constructed by OR-ing one or more of the following values:

DOOR_UNREF

Delivers a special invocation on the door when the number of descriptors that refer to this door drops to one. In order to trigger this condition, more than one descriptor must have referred to this door at some time. DOOR_UNREF_DATA designates an unreferenced
invocation, as the argp argument passed to server_procedure. In the case of an unreferenced invocation, the values for arg_size, dp and n_did are 0. Only one unreferenced
invocation is delivered on behalf of a door.

DOOR_UNREF_MULTI

Similar to DOOR_UNREF, except multiple unreferenced invocations can be delivered on the same door if the number of descriptors referring to the door drops to one more than once. Since an additional reference may have been passed by the time an unreferenced invocation
arrives, the DOOR_IS_UNREF attribute returned by the door_info(3C) call can be used to determine if the door is still unreferenced.

DOOR_PRIVATE

Maintains a separate pool of server threads on behalf of the door. Server threads are associated with a door's private server pool using door_bind(3C).

DOOR_REFUSE_DESC

Any attempt to call door_call(3C) on this door with argument descriptors will fail with ENOTSUP. When this flag is
set, the door's server procedure will always be invoked with an n_desc argument of 0.

DOOR_NO_CANCEL

Clients which abort calls to door_call() on this door will not cause the cancellation of the server thread handling the request. See cancellation(5).

The descriptor returned from door_create() will be marked as close on exec (FD_CLOEXEC). Information about a door is available for all clients of a door using door_info(). Applications concerned with security should not place secure
information in door data that is accessible by door_info(). In particular, secure data should not be stored in the data item cookie.

By default, additional threads are created as needed to handle concurrent door_call() invocations. See door_server_create(3C) for
information on how to change this behavior.

A process can advertise a door in the file system name space using fattach(3C).

After creation, door_setparam(3C) can be used to set limits on the amount of data and descriptors clients can send over the door.